X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=7b3fd18bb03cd66df479dd50ca7ec7c84b6226e6;hp=4551c39d4402eaa995c9a5ebeab8ffdb47e88a06;hb=daf0fe1f57337d33f9e0af5a8aa8ef0868b20417;hpb=377d77dbe922b99ee34d686e4fe180698a9b535a

diff --git a/src/search.cpp b/src/search.cpp
index 4551c39d..7b3fd18b 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -151,7 +151,7 @@ namespace {
   Value value_to_tt(Value v, int ply);
   Value value_from_tt(Value v, int ply);
   void update_pv(Move* pv, Move move, Move* childPv);
-  void update_cm_stats(Stack* ss, Piece pc, Square s, int bonus);
+  void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus);
   void update_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietsCnt, int bonus);
 
 } // namespace
@@ -183,22 +183,25 @@ void Search::init() {
 }
 
 
-/// Search::clear() resets search state to its initial value, to obtain reproducible results
+/// Search::clear() resets search state to its initial value
 
 void Search::clear() {
 
+  Threads.main()->wait_for_search_finished();
+
+  Time.availableNodes = 0;
   TT.clear();
 
   for (Thread* th : Threads)
   {
       th->counterMoves.fill(MOVE_NONE);
-      th->history.fill(0);
+      th->mainHistory.fill(0);
 
-      for (auto& to : th->counterMoveHistory)
+      for (auto& to : th->contHistory)
           for (auto& h : to)
               h.fill(0);
 
-      th->counterMoveHistory[NO_PIECE][0].fill(CounterMovePruneThreshold - 1);
+      th->contHistory[NO_PIECE][0].fill(CounterMovePruneThreshold - 1);
   }
 
   Threads.main()->callsCnt = 0;
@@ -250,7 +253,7 @@ void MainThread::search() {
 
   if (rootMoves.empty())
   {
-      rootMoves.push_back(RootMove(MOVE_NONE));
+      rootMoves.emplace_back(MOVE_NONE);
       sync_cout << "info depth 0 score "
                 << UCI::value(rootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
                 << sync_endl;
@@ -274,13 +277,13 @@ void MainThread::search() {
   // the UCI protocol states that we shouldn't print the best move before the
   // GUI sends a "stop" or "ponderhit" command. We therefore simply wait here
   // until the GUI sends one of those commands (which also raises Threads.stop).
-  if (!Threads.stop && (Limits.ponder || Limits.infinite))
-  {
-      Threads.stopOnPonderhit = true;
-      wait(Threads.stop);
-  }
+  Threads.stopOnPonderhit = true;
 
-  // Stop the threads if not already stopped
+  while (!Threads.stop && (Threads.ponder || Limits.infinite))
+  {} // Busy wait for a stop or a ponder reset
+
+  // Stop the threads if not already stopped (also raise the stop if
+  // "ponderhit" just reset Threads.ponder).
   Threads.stop = true;
 
   // Wait until all threads have finished
@@ -334,11 +337,10 @@ void Thread::search() {
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
   for (int i = 4; i > 0; i--)
-     (ss-i)->history = &this->counterMoveHistory[NO_PIECE][0]; // Use as sentinel
+     (ss-i)->contHistory = &this->contHistory[NO_PIECE][0]; // Use as sentinel
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
-  completedDepth = DEPTH_ZERO;
 
   if (mainThread)
   {
@@ -437,10 +439,7 @@ void Thread::search() {
                   }
               }
               else if (bestValue >= beta)
-              {
-                  alpha = (alpha + beta) / 2;
                   beta = std::min(bestValue + delta, VALUE_INFINITE);
-              }
               else
                   break;
 
@@ -499,7 +498,7 @@ void Thread::search() {
               {
                   // If we are allowed to ponder do not stop the search now but
                   // keep pondering until the GUI sends "ponderhit" or "stop".
-                  if (Limits.ponder)
+                  if (Threads.ponder)
                       Threads.stopOnPonderhit = true;
                   else
                       Threads.stop = true;
@@ -553,7 +552,7 @@ namespace {
     Value bestValue, value, ttValue, eval;
     bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
     bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
-    Piece moved_piece;
+    Piece movedPiece;
     int moveCount, quietCount;
 
     // Step 1. Initialize node
@@ -594,7 +593,7 @@ namespace {
     assert(0 <= ss->ply && ss->ply < MAX_PLY);
 
     ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
-    ss->history = &thisThread->counterMoveHistory[NO_PIECE][0];
+    ss->contHistory = &thisThread->contHistory[NO_PIECE][0];
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 
@@ -626,14 +625,14 @@ namespace {
 
                 // Extra penalty for a quiet TT move in previous ply when it gets refuted
                 if ((ss-1)->moveCount == 1 && !pos.captured_piece())
-                    update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+                    update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
             }
             // Penalty for a quiet ttMove that fails low
             else if (!pos.capture_or_promotion(ttMove))
             {
                 int penalty = -stat_bonus(depth);
-                thisThread->history.update(pos.side_to_move(), ttMove, penalty);
-                update_cm_stats(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty);
+                thisThread->mainHistory.update(pos.side_to_move(), ttMove, penalty);
+                update_continuation_histories(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty);
             }
         }
         return ttValue;
@@ -685,9 +684,9 @@ namespace {
             eval = ss->staticEval = evaluate(pos);
 
         // Can ttValue be used as a better position evaluation?
-        if (ttValue != VALUE_NONE)
-            if (tte->bound() & (ttValue > eval ? BOUND_LOWER : BOUND_UPPER))
-                eval = ttValue;
+        if (   ttValue != VALUE_NONE
+            && (tte->bound() & (ttValue > eval ? BOUND_LOWER : BOUND_UPPER)))
+            eval = ttValue;
     }
     else
     {
@@ -737,7 +736,7 @@ namespace {
         Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;
-        ss->history = &thisThread->counterMoveHistory[NO_PIECE][0];
+        ss->contHistory = &thisThread->contHistory[NO_PIECE][0];
 
         pos.do_null_move(st);
         Value nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1)
@@ -779,7 +778,7 @@ namespace {
             if (pos.legal(move))
             {
                 ss->currentMove = move;
-                ss->history = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)];
+                ss->contHistory = &thisThread->contHistory[pos.moved_piece(move)][to_sq(move)];
 
                 assert(depth >= 5 * ONE_PLY);
                 pos.do_move(move, st);
@@ -804,11 +803,10 @@ namespace {
 
 moves_loop: // When in check search starts from here
 
-    const PieceToHistory& cmh = *(ss-1)->history;
-    const PieceToHistory& fmh = *(ss-2)->history;
-    const PieceToHistory& fm2 = *(ss-4)->history;
+    const PieceToHistory* contHist[] = { (ss-1)->contHistory, (ss-2)->contHistory, nullptr, (ss-4)->contHistory };
+    Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
 
-    MovePicker mp(pos, ttMove, depth, ss);
+    MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, contHist, countermove, ss->killers);
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
     improving =   ss->staticEval >= (ss-2)->staticEval
             /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */
@@ -852,7 +850,7 @@ moves_loop: // When in check search starts from here
 
       extension = DEPTH_ZERO;
       captureOrPromotion = pos.capture_or_promotion(move);
-      moved_piece = pos.moved_piece(move);
+      movedPiece = pos.moved_piece(move);
 
       givesCheck =  type_of(move) == NORMAL && !pos.discovered_check_candidates()
                   ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move)
@@ -910,8 +908,8 @@ moves_loop: // When in check search starts from here
 
               // Countermoves based pruning
               if (   lmrDepth < 3
-                  && (cmh[moved_piece][to_sq(move)] < CounterMovePruneThreshold)
-                  && (fmh[moved_piece][to_sq(move)] < CounterMovePruneThreshold))
+                  && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
+                  && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold)
                   continue;
 
               // Futility pruning: parent node
@@ -946,7 +944,7 @@ moves_loop: // When in check search starts from here
 
       // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;
-      ss->history = &thisThread->counterMoveHistory[moved_piece][to_sq(move)];
+      ss->contHistory = &thisThread->contHistory[movedPiece][to_sq(move)];
 
       // Step 14. Make the move
       pos.do_move(move, st, givesCheck);
@@ -978,11 +976,11 @@ moves_loop: // When in check search starts from here
                        && !pos.see_ge(make_move(to_sq(move), from_sq(move))))
                   r -= 2 * ONE_PLY;
 
-              ss->statScore =  cmh[moved_piece][to_sq(move)]
-                             + fmh[moved_piece][to_sq(move)]
-                             + fm2[moved_piece][to_sq(move)]
-                             + thisThread->history[~pos.side_to_move()][from_to(move)]
-                             - 4000; // Correction factor
+              ss->statScore =  thisThread->mainHistory[~pos.side_to_move()][from_to(move)]
+                             + (*contHist[0])[movedPiece][to_sq(move)]
+                             + (*contHist[1])[movedPiece][to_sq(move)]
+                             + (*contHist[3])[movedPiece][to_sq(move)]
+                             - 4000;
 
               // Decrease/increase reduction by comparing opponent's stat score
               if (ss->statScore > 0 && (ss-1)->statScore < 0)
@@ -1061,8 +1059,8 @@ moves_loop: // When in check search starts from here
                   ++static_cast<MainThread*>(thisThread)->bestMoveChanges;
           }
           else
-              // All other moves but the PV are set to the lowest value: this is
-              // not a problem when sorting because the sort is stable and the
+              // All other moves but the PV are set to the lowest value: this
+              // is not a problem when sorting because the sort is stable and the
               // move position in the list is preserved - just the PV is pushed up.
               rm.score = -VALUE_INFINITE;
       }
@@ -1118,13 +1116,13 @@ moves_loop: // When in check search starts from here
 
         // Extra penalty for a quiet TT move in previous ply when it gets refuted
         if ((ss-1)->moveCount == 1 && !pos.captured_piece())
-            update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+            update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
     }
     // Bonus for prior countermove that caused the fail low
     else if (    depth >= 3 * ONE_PLY
              && !pos.captured_piece()
              && is_ok((ss-1)->currentMove))
-        update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth));
+        update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth));
 
     if (!excludedMove)
         tte->save(posKey, value_to_tt(bestValue, ss->ply),
@@ -1215,9 +1213,9 @@ moves_loop: // When in check search starts from here
                 ss->staticEval = bestValue = evaluate(pos);
 
             // Can ttValue be used as a better position evaluation?
-            if (ttValue != VALUE_NONE)
-                if (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER))
-                    bestValue = ttValue;
+            if (   ttValue != VALUE_NONE
+                && (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER)))
+                bestValue = ttValue;
         }
         else
             ss->staticEval = bestValue =
@@ -1244,7 +1242,8 @@ moves_loop: // When in check search starts from here
     // to search the moves. Because the depth is <= 0 here, only captures,
     // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
     // be generated.
-    MovePicker mp(pos, ttMove, depth, to_sq((ss-1)->currentMove));
+    const PieceToHistory* contHist[4] = {};
+    MovePicker mp(pos, ttMove, depth, &pos.this_thread()->mainHistory, contHist, to_sq((ss-1)->currentMove));
 
     // Loop through the moves until no moves remain or a beta cutoff occurs
     while ((move = mp.next_move()) != MOVE_NONE)
@@ -1388,13 +1387,14 @@ moves_loop: // When in check search starts from here
   }
 
 
-  // update_cm_stats() updates countermove and follow-up move history
+  // update_continuation_histories() updates histories of the move pairs formed
+  // by moves at ply -1, -2, and -4 with current move.
 
-  void update_cm_stats(Stack* ss, Piece pc, Square s, int bonus) {
+  void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
 
     for (int i : {1, 2, 4})
         if (is_ok((ss-i)->currentMove))
-            (ss-i)->history->update(pc, s, bonus);
+            (ss-i)->contHistory->update(pc, to, bonus);
   }
 
 
@@ -1411,20 +1411,20 @@ moves_loop: // When in check search starts from here
 
     Color c = pos.side_to_move();
     Thread* thisThread = pos.this_thread();
-    thisThread->history.update(c, move, bonus);
-    update_cm_stats(ss, pos.moved_piece(move), to_sq(move), bonus);
+    thisThread->mainHistory.update(c, move, bonus);
+    update_continuation_histories(ss, pos.moved_piece(move), to_sq(move), bonus);
 
     if (is_ok((ss-1)->currentMove))
     {
         Square prevSq = to_sq((ss-1)->currentMove);
-        thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]=move;
+        thisThread->counterMoves[pos.piece_on(prevSq)][prevSq] = move;
     }
 
     // Decrease all the other played quiet moves
     for (int i = 0; i < quietsCnt; ++i)
     {
-        thisThread->history.update(c, quiets[i], -bonus);
-        update_cm_stats(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+        thisThread->mainHistory.update(c, quiets[i], -bonus);
+        update_continuation_histories(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
   }
 
@@ -1488,10 +1488,10 @@ moves_loop: // When in check search starts from here
     }
 
     // An engine may not stop pondering until told so by the GUI
-    if (Limits.ponder)
+    if (Threads.ponder)
         return;
 
-    if (   (Limits.use_time_management() && elapsed > Time.maximum() - 10)
+    if (   (Limits.use_time_management() && elapsed > Time.maximum())
         || (Limits.movetime && elapsed >= Limits.movetime)
         || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes))
             Threads.stop = true;